diff --git a/src/extensions/DiffusionPreCommitContentSizeHeraldField.php b/src/extensions/DiffusionPreCommitContentSizeHeraldField.php
index dce6ccb80..17be2b1cd 100644
--- a/src/extensions/DiffusionPreCommitContentSizeHeraldField.php
+++ b/src/extensions/DiffusionPreCommitContentSizeHeraldField.php
@@ -1,53 +1,60 @@
 <?php
 
 final class DiffusionPreCommitContentSizeHeraldField
   extends DiffusionPreCommitContentHeraldField {
 
   const FIELDCONST = 'diffusion.pre.content.diff.size';
 
   public function getHeraldFieldName() {
     return pht('Total files size (bytes)');
   }
 
   public function getFieldGroupKey() {
     return DiffusionChangeHeraldFieldGroup::FIELDGROUPKEY;
   }
 
   public function getHeraldFieldValue($object) {
 
     $adapter = $this->getAdapter();
     $hook = $adapter->getHookEngine();
     $repository = $hook->getRepository();
     $vcs = $repository->getVersionControlSystem();
     $total_size = 0;
 
     $ref = $adapter->getObject()->getRefNew();
     $changesets = $hook->loadChangesetsForCommit($ref);
 
 
     foreach($changesets as $change){
       $size = 0; $err = null;
       if($vcs == PhabricatorRepositoryType::REPOSITORY_TYPE_GIT) {
         list($size, $err) =
           execx("git cat-file -s %s:%s",
             $ref,
             $change->getFileName());
       } elseif($vcs == PhabricatorRepositoryType::REPOSITORY_TYPE_SVN) {
         $txid = $hook->getSubversionTransaction();
         list($size, $err) =
           execx("svnlook filesize -t %s %s %s",
             $txid,
             $repository->getLocalPath(),
             $change->getFileName());
       }
       $total_size += (int) $size;
     }
 
     return $total_size;
   }
 
   protected function getHeraldFieldStandardType() {
     return HeraldField::STANDARD_INT;
   }
 
+  function supportsObject($object) {
+    if($object->getRepository()->isHg()) {
+      return false;
+    }
+    return parent::supportsObject($object);
+  }
+
 }